MANCHESTER, England — British police arrested 10 people on suspicion of terrorist activities and searched properties Monday in Manchester and other cities during several raids.

The 10 were arrested “on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism,” according to the Greater Manchester Police.

Assistant Chief Constable Dave Whatton said the suspects were of North African and Iraqi Kurdish origin. Seven were arrested in Manchester and three elsewhere in central and northern England.

Police also searched several properties in the city. The Dolphin takeaway restaurant south of Manchester's downtown was cordoned off and guarded by uniformed officers.

Three weeks ago, police arrested eight men in London and southeastern England and seized a cache of explosives on March 30 in Britain’s biggest anti-terror operation since the Sept. 11, 2001, attacks.

With Europe already on a high state of alert after train bombings in Madrid killed 191 people in March, police have warned Britons to remain vigilant to the threat of terror attacks.

Britain, Washington’s closest ally in the “war on terror” and in toppling Iraqi leader Saddam Hussein, has long feared it could be a prime target for Muslim extremists. London’s police chief has repeatedly said he believes an attack is inevitable.

A radical Muslim cleric said in a weekend interview with a Portuguese magazine that several Islamic militant groups in London were preparing attacks in Britain.

“It’s inevitable because several (attacks) are being prepared by several groups,” Sheikh Omar Bakri Muhammad told Lisbon’s Publica magazine from London, where he is based.

One “very well organized” group in London calling itself al-Qaida Europe “has a great appeal for young Muslims,” he said. “I know that they are ready to launch a big operation.”